Iowa Association of Naturalists Iowa's Plants
Iowa's Shrubs and Vines Iowa Association of Naturalists
The Iowa Association of Naturalists (IAN) is a nonprofit organization of people interested in promoting the development of skills and education within the art of interpreting the natural and cultural environment. IAN was founded in 1978 and may be contacted by writing the Conservation Education Center, RR 1, Box 53, Guthrie Center, IA 50115.
Iowa's Plants Booklet Series
Plants are a beautiful and important part of nature in Iowa. To assist educators in teaching their students about the common plants of Iowa, the Iowa Association of Naturalists has created a series of booklets which offer a basic, understandable overview of Iowa's plants, their ecology, and their benefits and dangers to people. The seven booklets in this series include:
Iowa's Spring Wildflowers (IAN-301) Iowa's Summer and Fall Wildflowers (IAN-302) Benefits and Dangers of Iowa Plants (IAN-303) Iowa's Trees (IAN-304) Seeds, Nuts, and Fruits of Iowa Plants (IAN-305) Iowa's Mushrooms and Nonflowering Plants (IAN-306) Iowa's Shrubs and Vines (IAN-307)
For ordering information about these and other IAN publications, please see the back cover of this booklet.
The Iowa Plants booklet series is published by the Iowa Association of Resource Enhancement Naturalists with grants from the REAP And Protection Conservation Education Board and the Education Board Iowa Conservation Education Council (ICEC), 1994.
Review Committee Cele Burnett, Environmental Education Coordinator, Story County Conservation Board Dan Cohen, Naturalist, Buchanan County Conservation Board Jean Eells, Environmental Education Coordinator, Hamilton County Conservation Board Judy Levings, State 4-H Youth Development Specialist, Iowa State University Stacey Snyder Newbrough, Freelance Naturalist and Librarian, Pocahontas, IA Jim Pease, Extension Wildlife Specialist, Iowa State University Diane Pixler, Naturalist, Marshall County Conservation Board Editorial Board Text: Dan Cohen Illustrations: Mark Müller Layout and Design: MJC Associates, Ankeny, Iowa Published by: Iowa Association of Naturalists
Iowa's Shrubs and Vines 1 Iowa's Shrubs and Vines Shrubs and Vines
Plants come in many forms. Trees are the tallest plants and usually have a single woody stem called a trunk. Smaller plants that have several woody stems are called shrubs. Those plants that climb and twist along the ground and on taller shrubs and trees are called vines. The showier forbs are the wildflowers and herbs that grow in woodland, wetland, and grassland areas. Grasses usually have less con- spicuous flowers and tall, slender stems and leaves. Small nonflowering plants such as mosses, liver- worts, and algae often cover the rocks, logs, and ground where there is more moisture. Together, these groups of plants provide the basis for natural communities. The shrubs and vines are especially important in these communities as they provide food and shelter for a variety of wildlife.
2 Iowa Association of Naturalists The Forest Hotel Woodland plants are arranged in several vertical layers, like the floors of a multi-level hotel. Beneath the woodland floor is the basement contain- ing tunnels and burrows that are home to a variety of unique animals. The woodland floor may be covered by mosses, fungi, and low-growing wildflow- ers. The next level of the “forest hotel” may consist
Canopy
Understory
Shrub and Vine Layer
Floor
Basement
of young trees and shrubs and vines. Smaller trees make up the understory layer of the hotel. The penthouse suite is the high canopy which forms the green ceiling of the woodland. Each of these layers supports a variety of wildlife, dependent on woodland plants. Each spring, the woodland seems to come to life one layer at a time as lower levels of the “hotel” become green and bloom before the higher levels leaf out and block out sunlight.
Iowa's Shrubs and Vines 3 The Shrub Layer Iowa’s shrubs and vines are most common in woodlands, especially along woodland edges and openings where they can receive sunlight. Shrubs are usually less than 15 feet tall, and vines can be seen at almost any height, trailing along the ground or climbing to the tops of the tallest trees. Some- times the terms “shrub” and “vine” are con- fusing to people. Although blackberries and other berry bushes are technically shrubs, people often say they are “picking ber- ries from the vine.” And some vines, such as poison ivy, may creep along the ground and form dense, shrub- like clumps. Because small trees such as sumacs and chokecherry grow in the vertical shrub forest layer, they too are often referred to as shrubs, even though they usually have a single woody stem. Shrubs are identifiable by their clonal pattern of growth, with several woody stems spreading outward from a single point.
Small tree
Shrub
Vine
4 Iowa Association of Naturalists Iowa’s Shrubs and Small Trees
Each spring, before the woodland canopy be- comes leafy and blocks sunlight, shrubs and small trees become green and begin producing flowers. Gooseberry, honeysuckle, crabapples, and choke cherries produce their flowers early in spring. By summer, shrubs and “shrubby” trees are usually producing an abundance of berries or other fruits. Some of these fruits, such as dogwood berries, may persist late into autumn and provide an important source of food for wildlife. The foliage of shrubs such as sumacs, gooseberries, and dogwoods are among the first to change color in autumn. They also pro- duce some of the most brilliant colors, making them easy to identify at a distance.
Thorny Thickets Many Iowa woodlands contain a thick growth of shrubs and vines. Shrubby woodlands are a re- minder that many of our woodlands were at one time pastured. Cattle choose not to bite into thorny shrubs, allowing prickly plants to survive and dominate an area that has been grazed. Thorny shrubs and less tasty plants that were not eaten by cattle are common in Iowa woodlands. Examples are shrubs and small trees such as gooseberries, honey locust, hawthorn, prickly ash, and multiflora rose. The shrub layer is less thick in well-developed and undis- turbed forests.
Gooseberry (Ribes missouriense) is a thorny shrub. The leaves are approximately two inches long and have rounded lobes that look some- what like a goose’s foot. The berries are green, changing to purple as they ripen. The green berries are very sour but become less sour as they turn purple. Gooseberries provide thorny cover for wildlife such as mice, rabbits, Gooseberry and songbirds and provide food for both animals and people.
Iowa's Shrubs and Vines 5 Blackberry (Rubus allegheniensis) and black raspberry (Rubus occidentalis) produce some of the most delicious fruits in Iowa woodlands. Both grow as rambling thorny shrubs, but blackberry stems are taller and more robust, sometimes growing to a length of ten feet. Blackberry leaflets are woolly underneath, while black raspberries are not. Black- berry stems turn a maroon color as they age, but black raspberry stems are somewhat whitish. Showy white blackberry flowers bloom in May and Black Raspberry June and produce the tasty aggregate fruits in July and August. Black raspberries begin blossoming as early as April with fruits maturing in June and July. All native raspberries have characteristic compound leaves with three to seven toothed leaflets and thorny branches.
Prickly ash (Xanthoxylum americanum) is a shrub or small tree that sometimes forms dense thorny thickets. The compound leaves with toothed egg-shaped leaflets are similar to those of ash trees. The “prickles” are found as pairs flanking the base of leaf stems and blossoms and along the leaf stalks. Prickly ash produces small green, reddish brown, or orange berries. The shrub is usually less than ten feet tall and is sometimes called “toothache tree” because chewing the berries, leaves, or bark has a numbing effect in the mouth. The berries produce a citrus smell and are not preferred by wildlife. Prickly ash flowers in April and May and produces berries from July through September. Prickly Ash Hawthorns (Crataegus spp.) grow either as dense shrubs or small trees. There are many species of hawthorns, but all have sharp thorns one to three inches long that are without buds or leaves. They produce small applelike fruits that may be yellow or reddish in color. Al- though hawthorns are considered a “weed” in farm pastures, thorny thickets provide important nest- ing habitat for birds along wood- land edges. The fruits, which may remain on the shrubs through the winter, are an impor- tant food for a variety of birds and mammals.
Hawthorn
6 Iowa Association of Naturalists Other Common Shrubs Not all woodland shrubs are thorny. Many, like of Iowa Woodlands the various common species of dogwood, have soft leaves and stems and produce fragrant flowers in the spring and berries during the summer. The shrub layer of an Iowa woodland is a wildlife grocery store of berries and other fruits and seeds. Dogwoods, hazelnuts, honeysuckle, elderberry, and witch-hazel may all be seen growing in Iowa woodlands and grassland edges.
Red-osier dogwood (Cornus stolonifera) is a medium-sized shrub with bright red twigs. It grows to a height of less than 10 feet and is usually found in wet areas along woodland edges. The two- to five- inch oval leaves have widely spaced veins and are whitish on the underside. All dogwoods produce flowers and fruits that provide food for wildlife. Dog- wood twigs are eaten by deer and rabbits. Red-osier dogwood produces white berries from July through October. Red-osier Dogwood Hazelnut (Corylus americana) is a medium-sized shrub with broad, rounded, doubly-toothed leaves. The twigs and leaf stems have stiff hairs that give the shrub a rough feel. The nuts, sometimes called filberts, have a thin, raggedy edged, hairy husk. A wide variety of wildlife as well as people collect the tasty nuts during the late summer months. Hazel- nuts are more common in the eastern part of the state.
Hazelnut
Iowa's Shrubs and Vines 7 Elderberry (Sambucus canadensis) is a shrub that usually grows to a height of four to eight feet. The large compound leaves have many oval leaflets. An identifying characteristic of elder- berry is the white pith that is obvious when the larger twigs are broken. Elderberry flowers and fruits grow as large flat-topped clusters. The dark purple berries are often used to make jams, jellies, pies, and wines. Look for the berries during late summer and autumn.
Elderberry
Shrubby Grassland Invaders Over time, Iowa prairies may be slowly trans- formed into woodlands. Without prairie management or natural controls, shrubs and other woody plants may take over the grassland habitat. Shrubs and small trees are the first of the woody invaders to grow in a grassland. Plants such as wild rose, smooth sumac, dogwoods, and red cedar are among the first plants to enter the grasslands.
8 Iowa Association of Naturalists Wild rose (Rosa carolina) is the state flower of Iowa. It grows as a woody shrub in open woodlands, woodland edges, and prairies. The flowers are pink- purple with yellow stamens and may be two inches wide. They bloom from June through September. The leaves are oval, sharply toothed, and divided into five to seven leaf- lets. Rose thorns are more conspicuous on larger woodier stems. Rose fruits, called hips, remain on the plant through winter and provide a source of vitamin C.
Smooth sumac (Rhus glabra) is a small tree or shrub with smooth branches and large compound leaves that turn brilliant purple in early autumn, making them easy to identify at a distance. Clumps of red, hairy persistent fruits appear in autumn and provide food for a variety of wildlife throughout fall Wild Rose and winter. Poison ivy is in the same genus as the sumacs, and although smooth sumac is not poisonous to the touch, poison sumac does contain a dangerous skin irritant. Poison sumac, however, does not exist in Iowa.
Smooth Sumac
Iowa's Shrubs and Vines 9 Vines
Vines are plants that have adapted to life in shady woodlands by being able to climb up or creep toward available sunlight. Most vines will crawl on the ground or climb over rocks and living and dead plants. They may appear to be low-growing plants or bushes, or their leaves may be mistaken for the leaves of the tree they are climbing. Some vines, such as the non-native trumpet vine, produce showy flowers. Wild grape produces edible fruits. However, fruits from the other vines are not edible. The only vine in Iowa that is poisonous to the touch is poison ivy.
Climbing to Sunlight There is a definite advantage for plants that can reach through dense vegetation and find adequate sunlight. Without sunlight, green plants cannot photosynthesize their food. Trees and, to a lesser degree, shrubs are able to produce stout woody stems that can support their leaves at a greater height. These plants expend a lot of energy to create the materials for this woody ladder. But vines have adapted to reach- ing high above other plants without having to create an “energy-expensive” woody stem. In order to climb to sunlight, vines use several devises. Plants such as wild cu- cumber and wild grape have Wild Grape coiled tendrils that naturally Tendrils
10 Iowa Association of Naturalists wrap around any object the plant encounters. The tendrils are touch sensitive so that they grow more slowly on the side that is in contact with an object. The other side continues to grow at the normal rate and eventually coils over the touched side. Tendrils may be formed from modified branches, petioles, or leaflets. In Virginia creeper, the tips of the tendrils have small adhering discs, called hold- fasts. The holdfasts act to hold the growing plant on its supporting structure. Poison ivy and bittersweet climb with- out tendrils. To climb, they use twining stems that grow in a spiral fashion that lets them use other plants as a trellis. Poison ivy sometimes sends out aerial roots as it climbs, but unlike tendrils, these roots do not coil.
Poison Ivy Twining Stems & Aerial Roots
Virginia Creeper Holdfasts
Iowa's Shrubs and Vines 11 Iowa’s Vines A few vines grow in woodlands throughout Iowa. Virginia creeper, wild grape, and poison ivy are especially common. Other vines found throughout Iowa are bittersweet, wild cucumber, moonseed, and greenbrier. Trumpet vine is native only to southeast Iowa but has escaped from landscaped yards to live in the wild throughout the state. Vines grow throughout the woodland, adding layers of leaves, blossoms, and berries to all layers of the forest.
Virginia creeper (Parthenocissus quinquefolia) is a very common vine which can climb 40 feet or more using numerous tendrils and holdfasts. It is some- times called five-finger or five-leaf ivy because each leaf is divided into five leaflets. The leaves are green throughout the summer, but in early fall they change to a beautiful red or purple color. Occasionally a couple of leaflets may fall off, causing Virginia creeper to be confused with another common vine called poison ivy.
Poison ivy (Rhus radicans) is a vine which may take the form of a small plant, bush, vine, or small tree. Leaves are divided into three leaflets and grow alternately up the leaf stem. The plant is sometimes con- fused with young boxelder plants which also have three leaflets but grow opposite along the stem. Poison ivy is a plant that should be avoided but need not be feared. Most people are allergic to the oil which is produced on the leaves and stems of Virginia poison ivy. The poison can cause rashes and blisters Creeper
Poison Ivy
12 Iowa Association of Naturalists which may be painful. The reaction usually does not occur until at least 12 to 24 hours after contact with the plant and can normally be avoided by washing with warm water and strong soap. Poison ivy is not a danger to wildlife and is a source of food for birds which eat its berries. Poison oak is similar to poison ivy but does not grow in Iowa.
Wild grape (Vitis riparia) is a very Wild Grape common vine of Iowa woodlands. Grape vines sometimes climb to great heights, making use of many tendrils. The leaves grow alternately on the stem, are toothed, and have several shallow lobes. Wild grapes are edible for both people and wildlife. The fruits are small, dark, and sweet. Nearly 100 different species of songbirds and many other birds and mammals are known to feed on grapes.
Bittersweet (Calastrus scandens) is a thick vine of Iowa wood- lands. It grows as a twining stem and has no tendrils or aerial roots. The four-inch leaves are oval with a pointed tip and grow alternately along the vine. Bittersweet produces small inconspicuous flowers but is best known for its bright reddish orange fruits which persist into late autumn or winter. The scarlet berries are often collected for ornaments and decoration.
Bittersweet
Iowa's Shrubs and Vines 13 Wild cucumber (Echinocystis lobata) has a weak, usually green stem that climbs with the aid of tendrils. The leaves are rough and somewhat star- shaped with several pointed lobes. The characteris- tic fruit is a spiny egg-shaped capsule. Although commonly called a “cucumber,” it is not related to Wild cultivated cucumbers and is not edible. The vine is Cucumber also sometimes called “squirting cucumber” because the dry fruit dramatically breaks open and flings the four large seeds into the air.
Moonseed (Menispermum canadense) is a smooth vine with broad shallow-lobed leaves that climbs using green twining stems. White flowers begin blooming in May and produce fruits in September and Octo- ber. The fruits are black with a whitish powder. Moonseed fruits are poisonous, and care must be taken not to confuse them with wild grapes.
Moonseed
Greenbrier (Smilax rotundifolia) is a thorny vine that climbs using tendrils. The tendrils are at the base of the leaf stalks and remain after the leaves fall off. Leaves are rounded and somewhat heart- shaped, and the stem is woody and green. Greenbri- ers are low-growing vines that often resemble shrubs. They flower during May and June and produce black fruits that may remain on the vine through winter.
Greenbrier
14 Iowa Association of Naturalists Shrubs, Vines, and Wildlife
Shrubs in woodlands, woodland edges, fence rows, and open areas are often the most important plants for wildlife. Dense thickets, flowering shrubs, and a variety of berries, nuts, and other fruits make shrubs, vines, and small trees important places for winter cover, protection from predators, and sources of food throughout the year.
Iowa's Shrubs and Vines 15 Shrubs and vines provide a variety of delicious and long-lasting foods for wildlife. Some foods, such as wild grape, blackberries, serviceberries, and cherries, are especially tasty to wildlife and are quickly eaten. Other foods such as hawthorn and dogwood berries, although not immediately favored by wildlife, are long-lasting and provide an impor- tant source of food into the winter months. During the spring and summer months, berry-producing shrubs and small trees such as mulberry, chokecherry, serviceberry, plum trees, blackberry, and black raspberry provide food for songbirds and other wildlife. Deer, quail, chip- munks, and squirrels also feed on berries and on nuts, leaves, and stems of other shrubs. Blossom- ing dogwoods, honeysuckle, blackberry, trumpet vine, and other shrubby plants provide nectar for hummingbirds, butterflies, moths, and bees. Thicket-forming shrubs such as black raspberry and hawthorns provide important nesting cover. Virginia creeper, poison ivy, and especially grape vines also provide good summer cover and foods for wildlife. As autumn and winter approach, food and shelter become most important for wildlife. Plants such as dogwoods, wild plum, highbush cranberry, service- Chokecherry berry, red cedar, and Virginia creeper provide critical winter habitat. When the snow falls, bittersweet, sumac, hawthorn, and crabapple fruits persist on the leafless plants. Winter birds and mammals feed on the fruits and find shelter in the dense growth of shrubs and vines.
Chokecherry (Prunus virginiana) is a small tree or shrub with smooth gray bark. The simple leaves are sharply toothed and grow alternately on the stem. Chokecherries have attractive white flowers that produce berries from July through October. The small bitter purple berries are eaten by wildlife and are sometimes collected by people for jellies, jams, and pie filling. Smaller stems and bark are occasion- ally eaten by wildlife.
Serviceberry (Amelanchier laevis), also called Juneberry, is a beautiful shrub or small tree with pinkish red blossoms. The oval leaves are two to three inches long and toothed. Like other members of the rose family, the fruits are applelike. Although people use the fruits for jams and pies, most fruits are quickly eaten by a variety of birds and mammals. Serviceberry
16 Iowa Association of Naturalists Wild plum (Prunus americana) is closely re- lated to the cherry trees. Plum trees have simple toothed leaves and gray speckled bark. Unlike the cherries, most plum trees have thornlike structures. Fragrant white flowers blossom in spring. The yellow and red fruits are one-half to one inch in diam- eter and contain a single large seed. Like the cherries, plum trees provide food and cover for a variety of wildlife.
Wild Plum
Red mulberry (Morus rubra) is Iowa’s native mulberry bush. It may grow as a shrub or tree, sometimes growing very tall. The leaves have varying lobes and are toothed. Taller trees, which may grow from 30 to 50 feet, have a reddish brown trunk. It is a relatively uncommon tree. On the other hand, the non-native white mulberry is widespread. It is distinguished by the orange- brown bark on young trees and branches of large trees. Its fruit is rarely white. Mulberry fruits look like elongated blackberries and are a favorite food of many songbirds. People also enjoy the tasty berries that usually are collected in June and July. The seeds are often spread by birds after passing through their digestive tracts.
Red Mulberrry
Iowa's Shrubs and Vines 17 Summary
Shrubs and vines are an important part of Iowa woodlands and grassland edges. Shrubs and small trees make up a forest layer that is rich in food and provides winter cover for wildlife. Unlike shrubs and trees, vines do not have thick, rigid stems that can carry them to sunlight. Instead, they use tendrils, holdfasts, and twining stems to help them climb or
crawl to sunlight. Shrubs, small trees, and some types of vines may appear “bushy,” and all are some- times grouped as “shrubs.” True shrubs have several woody stems and are usually less than 15 feet tall. Although some types of shrubs and vines may be dangerous to eat, nearly all are safe to touch, if you don’t mind a few thorns. The exception is poison ivy which is found throughout the state. Poison sumacs are also poisonous to the touch but are not currently known to exist in Iowa.
18 Iowa Association of Naturalists Many Iowa shrubs are thorny and remind us that much of our state has, in recent times, been pas- tured. Thorny thickets make excellent protective cover for many types of wildlife. Many shrubs pro- duce beautiful flowers or tasty fruits enjoyed by both people and wildlife. The diversity of shrubs, vines, and small trees along woodland-grassland edges makes for a diversity of wildlife.
Useful Resources
“Forest and Shade Trees of Iowa,” P.J. Van Der Linden and D. R. Farrar, Iowa State University Press, 1993.
“The Illustrated Book of Trees,” William C. Grimm, Stackpole, 1983.
Iowa State University Extension publications, contact your county extension office.
“Our Northern Shrubs and How To Identify Them,” Harriet Keeler, 1969.
“Poisonous Plants of the Central United States,” H.A. Stephens, University Press KS, 1980.
“Trees and Shrubs,” Peterson Field Guides, George A. Petrides, 1986.
“Wild Edible Fruits and Berries,” Marjorie Furlong and Virginia Pill, Naturegraph, 1974.
Iowa's Shrubs and Vines 19 Notes
20 Iowa Association of Naturalists Iowa's Shrubs and Vines is one in a series of seven booklets that are part of the Iowa Plants Series. The booklets in the series include:
Iowa Plants Iowa's Spring Wildflowers (IAN-301) Iowa's Summer and Fall Wildflowers (IAN-302) Benefits and Dangers of Iowa Plants (IAN-303) Iowa's Trees (IAN-304) Seeds, Nuts, and Fruits of Iowa Plants (IAN-305) Iowa's Mushrooms and Other Nonflowering Plants (IAN-306) Iowa's Shrubs and Vines (IAN-307)
The Iowa Association of Naturalists also has produced five other booklet series that provide readers with a clear, understandable overview of topics concerning the Iowa environment and conservation. The booklets included in each of the other five series are listed below.
Iowa Physical Environment Series Iowa Weather (IAN-701) Iowa Geology and Fossils (IAN-702) Iowa Soils (IAN-703)
Iowa Wildlife Series Iowa Mammals (IAN-601) Iowa Winter Birds (IAN-602) Iowa Nesting Birds (IAN-603) Iowa Reptiles and Amphibians (IAN-604) Iowa Fish (IAN-605) √ Booklets may be ordered Iowa Insects and Other Invertebrates (IAN-606) through the Iowa State University Extension Service at a Iowa's Natural Resource Heritage cost of $1.00 per booklet. When Changing Land Use and Values (IAN-501) ordering, be sure to use the IAN Famous Iowa Conservationists (IAN-502) number to the right of each listed Iowa's Environmental Laws (IAN-503) booklet title. Please send written Conservation Careers in Iowa (IAN-504) orders and payment to:
Iowa Wildlife and People ISU Extension Service Iowa Wildlife and Management (IAN-401) Printing and Publications Building Keeping Iowa Wildlife Wild (IAN-402) Iowa State University Misconceptions About Iowa Wildlife (IAN-403) Ames, IA 50011 State Symbols of Iowa (IAN-404) 515-294-5247 Iowa Food Webs and Other Interrelationships (IAN-405) Natural Cycles in Iowa (IAN-406) Iowa Biodiversity (IAN-407) Adapting to Iowa (IAN-408) This publication is printed on recycled paper. Iowa's Biological Communities Iowa's Biological Communities (IAN-201) Iowa Woodlands (IAN-202) Iowa Prairies (IAN-203) Iowa Wetlands (IAN-204) Iowa Waterways (IAN-205)
Iowa Environmental Issues Iowa Habitat Loss and Disappearing Wildlife (IAN-101) Iowa Air Pollution (IAN-102) Iowa Water Pollution (IAN-103) Iowa Agricultural Practices and the Environment (IAN-104) People, Communities, and Their Iowa Environment (IAN-105) Energy In Iowa (IAN-106) Iowa Waste Management (IAN-107)